Wireless Local Area Networks (WLAN) can provide a user with such amenities as high-speed wireless Internet access and an alternative for telephony services as well as other real-time applications. Such WLANs use radio frequency transmissions to communicate between roaming communications units and access points. The access points provide wireless service to a small coverage area and are connected to an infrastructure that electronically connects all of the access points to a data network including, routers, host servers, and all available internet services. The wired infrastructure and the access points make up an information distribution network used for the transfer of information and for communications.
In conventional WLANs, when a communications unit operating with a first access point detects that it is losing or has lost wireless service at its current location, it probes channels to locate other available access points. Specifically, the standard IEEE 802.11 WLAN operation for probing is for the communications unit to send a probe request to a second particular access point and for that access point to send a probe response as soon as it can send such a response based on a traffic contention algorithm. The communications unit then requests an association with the second access point. However, in operation, the probing and association processes consume battery power and typically take hundreds of milliseconds. During this time, the user can experience unsatisfactory service, or even worse, a dropped call or link. In addition to a loss of time, a delay or loss of packets may occur before the communications unit discovers that a handover is required.
Therefore, what is needed is a method and apparatus for providing a fast handover of a link or a connection between a first and a second access point within a wireless communications network.